+29 Assuming you meant
3.2 × 10 (-2) + 3.2 × 10 (-4) + 2.8 × 10 (-2) the answer is -248
+9673 I will do the assumption that you mean \(3.2\times 10^{-2} + 3.2\times 10^{-4}+2.8\times 10^{-2}\) because I see the pattern of scientific notation. (PS: I am learning scientific notation in school maths lessons too :) but actually not any teacher knows that I do self-learning for maths and I have already gone through this 3 years ago :P)
\(3.2\times 10^{-2} + 3.2\times 10^{-4}+2.8\times 10^{-2}\\ = 3.2\times 10^{-2} + 0.032\times 10^{-2}+2.8\times 10^{-2}\\ =(3.2 + 0.032 + 2.8)\times 10^{-2}\\ = 6.032 \times 10^{-2}\)
